A conventional high-frequency module disclosed in Japanese Patent Unexamined Publication No. H11-331015, for example, will be described with reference to the drawings. FIG. 19 is a cross-sectional view of a high-frequency module using a conventional shield case. FIG. 20 is a bottom view of the shield case.
In the conventional high-frequency module, electronic components 2 and 3 are mounted on upper face 1a of printed circuit board 1. The high-frequency module is provided by oscillator 4 including electronic component 2 on printed circuit board 1 and PLL circuit 5 including electronic component 3. It is noted that oscillator 4 is an example of a first circuit block and PLL circuit 5 is an example of a second circuit block.
Shield case 6 is attached to printed circuit board 1 so that top face 6a covers electronic components 2 and 3. Then, connection section 7 is provided at the tip end of side plate 6b provided by bending top face 6a. Connection section 7 is a projection having a width of 6 mm and a length of 0.7 mm. Shield case 6 and printed circuit board 1 are connected by soldering connection section 7 with terminal section 8 provided at side face section 1b of printed circuit board 1.
Then, the center part of shield case 6 is integrated with barrier 6c provided by partially cutting and bending shield case 6 from top face 6a. At the tip end of barrier 6c, leg 9 is provided. On the other hand, a position on printed circuit board 1 corresponding to leg 9 is provided with through hole 10. Leg 9 is inserted into through hole 10. When leg 9 is soldered in through hole 10, printed circuit board 1 is connected with shield case 6.
In shield case 6 as described above, barrier 6c is formed by partially cutting and bending shield case 6 from top face 6a. Thus, hole 11 having a size corresponding to the size of barrier 6c is formed in shield case 6. Due to hole 11 formed in top face 6a, the conventional high-frequency module using shield case 6 as described above had a problem of poor shielding performance.